The present invention relates to optical data disks such as compact disks (CDs) and video disks (DVDs) that have central circular locating openings, and more particularly to devices for holding and/or protectively enclosing such disks for storage of same.
Data disks such as compact disks and video disks typically have large amounts of digitally stored information that is optically readable through a transparent bottom layer of the disk by a movable head during rotation of the disk. The information is arranged in one or more tracks that are covered by a thin protective top layer of the disk that can have labeling applied thereto such as by silkscreening. Normal handling of the disk can result in scratching of the bottom layer, resulting in loss of data by interference with the optical path such as by loss of focus and/or lateral image displacement. Also, data can be lost by scratching of the protective layer which is typically very thin, on the order of 20 microns, resulting in removal of information from a vapor deposited metal layer that is only about 0.1 micron thick. Protective containers for the disks in common use have a central pedestal for supportively gripping the disc by engaging the central opening without contacting either side of the disk within data-containing regions thereof. Such containers typically have a ledge for contacting portions of an outer perimeter of the disk for stabilizing the disk against tipping on the pedestal. The disk is loaded into the container by lowering it onto the pedestal while gripping opposite perimeter portions, engagement with the pedestal being typically effected by simultaneous finger pressure against the disk proximate the central opening. Removal of the disk is similarly effected by finger pressure against the pedestal and simultaneous lifting at the perimeter portions.
Disk holders and containers of the prior art typically exhibit one or more of the following disadvantages:
1. They are ineffective in that the disk can easily become disengaged from the pedestal in normal and/or expected handling of the device;
2. They have structural components that are likely to be snagged or damaged during normal use and handling;
3. They are difficult to operate as to engagement and/or disengagement of the disk; and
4. They are excessively complex, involving high tooling costs, expensive quality control, and/or high rejection rates in production.
Thus there is a need for a protective disk container that overcomes at least some of the disadvantages of the prior art.